Furnace lining



C. HART FURNACE LINING June 27, 1933.

Filed June 18 raies-rea .ieee a?, less erreur foi-'Fics cnr-rianne naar, or runnin, PENNSYLVANIA', AssieNon, BY ivrEsNn ASSIGNMENTS, or cuir-nerr Tro WELL-IAM Jamison", or rrrrneninrnin, PENNSYLVANIA Fun-NACE LINING y Appiicazion inea June is,

My invention relates to furnace linings and more particularly to linings for mechanical paddling furnaces.

i purpose of my invention is to provide a furnace lining with metallic strengthening ribs, and to paci; the spaces between the ribs ufitl'i refractory material. v

further purpose is to extend metallic races throughout tlie'body of the refractory lining of a furnace exposed to the charge i.' lt crushing .and breaking strains arising fro the charge, and particularly shock due to the rollingofthe Vpuddled ball about fun ace lining, will be borne by the metal braces rather than by the weaker refractory material While at the .same tiine'the lining 7 n n u I ofthe riesiredchemical properties Will consist braces. n

A further purpose is to strengthen exposed noi-tions of a furnace lining Which are'particularly subject to crushing and spalling, as for example, skimming and brealring'vvalls and mining varies, by extending metallic ribs l throughout the body of such Structures, and

desirably exposing them to the surface at prominent points to bear the additional 'L'trainsto'beinet there. Y

e. fur'le'iurpose is to build Va mechanical i'nace lining of metallic strips, parl ng ienactorynia iial between them to l iclziiess less thanthe strips, so that the f fnate elerations atthe stripsv and` depressions 'between the strips Will form 'an undulat-ing surface very desirable for mixing the i930. serial No. 461,893.

lFigure 1 is a side elevation of a mechanical puddling furnaceto Which my invention has been apped, half of which has been sectioned up the line 1 1 of Figure 2.

Figure 2 is a section taken on the line 2 2 of Figure 1 but omitting the stack and Y the suport-ing structure sho-Wn in Figure l.

Figure 3 is an enlarged fragmentary elevation of my furnace lining as viewed from the interior in a radial direction.

Figure e isa fragmentary section corresponding generally to Figure 2, but greatly enlarged. n

Figures 5 and G are generally similar to Figure 3, but show slight variations in the furnace lining structure.

Figure 7 is a fragmentary sectional perspective vievv of another modified form of my furnace lining. k

y Figure 8 corresponds generally to Figure 3y except that the strengthening ribs in the lining are differently disposed.

Referring to Figures 1 and 2, the furnace comprises generally an external metallic casing supported at either end by the heads 16 and 17, braced at'18 and 19 from the hubs 2O and'21. Thev hubs carry bands 22 and 23 which rest in and rotatek or oscillate upon rollers 24 and 25v in supports 26 and 27, so that the furnace may be rotated or oscillated as desired. The hub 21 also supports a driving band 28 having gear teeth 29 engagin the driving gear 30 on the shaft 31 of the motor 32, to turn the furnace.

Suitable gaseous or liquid fuel is admitted through the burner 33 from the pipe 34, controlled by ythe valve 35. Air is drawn in around the burner. kThe products of combustion from the furnace discharge through the neclr35 into the flue 3T and up the stack 38. The flue and the neck are desirably. in-V terrelated as at 39 in any suitable manner so that the furnace may rotate Without excessive loss of draft.

For charging and discharging, the Afurnace has a door 40, which may very desirably rbeinechanically controlled by the electric motor and speed reduction units 41, as through the driving connections at 4t2` and impart rotation to thescrevvs 43, supported in the bearings 44 of the collars 45. The collars 45 are pivoted at 4G to the lifting arms 47, pivotally secured to Jthe furnace casing at 48. The lifting arms 47 are secured to the door frame 40" at the pivotal and rotatable bearings 49. f

It will be understood that the description herein recited of the mechanical details of the furnace structure is entirely irrelevant to the claim features of my invention, and is given merely to make clear the drawing which I show of my best form.

As best seen in 1iigure 2, he furnace casing l5 supports a lining 50 about the interior, to hold the bottoni and the charge. Previous practice h as been to form this lining of some suitable, preferably basic, refractory material, as for example magnesite. Tvhile magnesite is a satisfary lining chemically it frequentiy fails due to mechanical shock when the wrought iron 4ball rolls over the lining and drops from the advancing side of the rotating furnace to a point near the bottom. y

Particularlyv where a projection of any kind extends into the furnace, the lining will suffer excessively from the constant pounding by the metal during its semi-solid .stagc'at the end of the puddling operation.

It has previouslybeen suggested in the patent to lilaccallum, No. l,lO6,725, that the roof and upper walls of steel furnaces may be formed of small independent pipe sections packed with refractory and set like bricks endwise in the furnace wall, refractory material being placed between them to serve as mortar. This is unsatisfactory because, vit greatly decreases the strength of the lining in a direction parallel to the surface, as the short pipes do not unite the lining wall.

rIhe above patent also proposes to build up a steel furnace roof of refractory filled in pockets formed by a metal frame. Maccallum of course does not propose to havev his roof lining come in contact with the charge,

and indeed it would be impossible under the conditions in a steel furnace.

In attempting to design a lining to stand the severe conditions of shock encountered in a mechanical puldling furnace, I have discovered that by extending ribs continuously along the lining and packing refractory between them I can robtain a much greater strength and stiffness in the plane of the surface, as :for example to resist the impact of the puddledball, and at the same time can assist in mixing the charge due to the maintained irregularity of the surface.

As seen in Figure 2, and more clearly in Figures 3 and 4, the ribs 5l extend the full length of the furnace and also along they ends to the opening at each end. Between the ribs 5l refractory7 material has been packed as at 52. This packed material may very desirably be magnesite.

My bracing strips 5l may be secured to the body l5 of the furnace as by brackets 53, seen in Figure 4. IVhile these brackets are desirable, they are not necessary for the proper use of my invention, because the great length of the ribs and their continuous packing with refractory material tends to give them igidity without attachment to the body of the furnace. lVhere ribs of considerable radial extent are used, as in the dam or breaking wall `54, the ribs will very desirably be united to the furnace casing because of the abnormal angular strains to which they will be subjected.

Even without the use of attaching means between the ribs and the external casing, my lining is very strong and firm. Additional firmness is imparted by extending the ribs radially inward across the ends as at 55, thus locking the ribs against slipping inward by virtue of the wedge action of the refractory material packed between the ribs at points 56. It will be seen that the refractory material fills a space between the ribs of increasing width as the radial distance from the axis increases. The wedge shaped packing of the refractory, while not necessary to my invention. is advantageous.

It will be seen in Figure 4 that the distance between the ribs at some point 57 near the inside of the lining cross section is less than that at the outside as at 58. The cavity between the ribs into which ythe refractory is packed thus has the general cross section of a trapesium, so that the refractory cannot v possibly slide inward, and it will be constantly held against the ribs by wedge action against their sides.

In Figures 1 to 4 I indicate that the ribs may be placed in generally radial planes. This has a distinct advantage in the application of my invention to a mechanical puddling furnace because the lining may conveniently have alternate projections and hollows extending in radial planes and serving to assist in the mixing of the metal.

In these figures I indicate that the metal ribs protrude relatively far inwardly as at .59, while the adjacent refractory material does not extend so far inwardly as at GO. Each strengthening rib in the lining will form a miniature mixing wall or breaker, while each hollow in the refractory between the ribs will permit metal iowing from the .ribs to lap over itself as it mounts the next slope to the succeeding rib.

This process will be continuously repeated as the furnace rotates or oscillates, so that the ribs will not only strengthen the entire lining, but will more particularly strengthen the inner projecting portions of the lining at the point where increased strength is most needed, that is, at the peak of the projection.

Since my invention is advantageous in providing miniature breaking walls about the llo VIG

hau

`packed between.

`:amarre entire lining, itv will of course much .increase the eiiicacy of .alarge breaking wall such as 54. The metal flowingover the wall 54 as the `furnace oscillates or rotates will encounterfnot only the general irregularity of the wall in outline, but also the local undulations due to the alternate ribsand bellows.

This advantage is supplementary to the desirable strengthening of the breaking wall by the ribs.

My invention is not restricted to mechanical puddling furnaces, nor is it limited to rotating or oscillating furnaces at all, nor

It offers considerable advantage in the construction of linings fory openhearths, air furnaces,

cement kilns, ovens and ina-ny other `metallurgical and industrial uses.

In Figures 5, 6, 7 and 8 I illustrate modified forms of my furnace lining. `'It will be understood that these formsmay beconsidered applied to the furnace of Figures 1 to 1l, or asmaking up part of the wall ofany other furnace `to which my invention might Vbe applied, whether it is movable or stationary, and whether ornot itis used in the mixing of wrought iron.

Vhere YFigures 5, 6, 7v and 8 vrepresent their respective forms applied to the furnace of Figures 1 to il, they dier from the'form of Figures 1 to 4 in the mode of disposing the ribs. In Figure 5 the ribs lextend circumferentially about the lining, with refractory-material 52 packed between the ribs.

This disposition is disadvantageous in the Vmaking of wrought iron because the ribs are not available to perform their most efficient mixing function, but nevertheless I consider this construction superior to the linings now in use, and anticipate that it may prove highly advantageous in furnaces other than ypuddling furnaces.

In Figure 6 the ribsd512 are spirally disposed, and have refractory material 522 isv advantageous because it'willfimpart a rotary motion to the puddled ball, tendingto make the ball spherical rather than ellipsoidal. The spiral ribswill also produce end mixing inthe liquid charge, becausethey will tend vto feed-the charge toward one-of the other of the ends of the furnace, avhere-the charge willlap over itself in striking the end l wall, thus obtaining a desirable type of mix- In Figure 'l' I show spirally disposed ribs 513 bracing a spiral mixing vane 61. The direction of the strengthening ribs 513 is here the same as that of the mixing vane so that no strengthening rib runs transverseto the mixing vane at any point. The ribs 513, forming part of the mixing vane, are much longer radially than the adjacent ribs 514.

It will be seen that the spiral mixing vane 61 will be much more effective in projecting The direction of the ribs Of course the ribs need not necessarily lie inthe plane of thev spiral vane,'but could extend for example in any of they directions shown in Figures-V to 6 and 8.

The use of spiral ribs 514 in the lining `proper concurrently .with the mixing vane,

while desiraole is not necessaryjto my invention, although the ribs 514y cooperate to supportthe mixingvane 6l and the lmixing' vane ribs 513, and will preferably be spiral along 'the same pitch` as the mixing vane.

Refractory material is packed between the ribs 5'13 at 523, and between the ribs 514 at 524. In'Figure 8 I show strengthening ribs 515 `and 51G runningtransversely with respect to one another. `short units extending only between the adj acent members of the transverse setl of ribs, and supported from the furnace body as shown in Figurel et, or else one or both sets ko'f ribs Vmay be slotted to interiit as desired. Refractory material 525' `is packed' in vthe `clesedspace between the ribs. It will be evident tha t, this form is distinctly advantageous, not onlyT because of its irregular surface which vwill assist in mixi|ng,ebut also because the strengthening ribs provide interlocking sup- .port in all directions. The interlocking ribs brace ene another and are effectively-metallic honeycomb.

Y IVhile I indicate that'refractory materialA One set of ribs may consist of or refractory crumbs, with or without binder;

Then I say that my strengthening ribs are exposed to the furnace interior or ex- `posed to the charge Imean thatfthe inner end of each'rib extends inward to substantially the same dist-ance or to a greater distance ythan the adjacent refractorymaterial, I do .notA means that some slight refractory covering over the rib may not exist, or that the rib will not be covered by the bottom or fettling, since this will ordinarily be the case.

The mere placing of a thin refractory coating over the end of the rib will not avoid the use of the broad principle of my invention, which is to support the greater part of the impact from the charge against the lining by the rib.

The infinite demands for furnace movable construction will doubtless suggest to designers the use of the lining of my invention in a great variety of furnaces and for many different uses in any particular furnace, but I believe that I am the vfirst to place in a furnace lining strengthening ribs perpendicular to the lining surface, exposed to the charge and extending for a substantial distance along the lining in any direction.

In view of my invention and disclosure variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain part or all of the benefits of my invention without copying the structure shown, and I, therefore, intend herein to claim all such in so far as they fall lwithin the reasonable spirit and scope of my invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a. rotatory or oscillating furnace, a furnace body,'means for turning the body about an axis, a furnace lining within the body having a surface parallel to the axis and having ends, and a plurality of metallic strengthening ribs, each rib being integral, being embedded in the lining and being exposed to the charge along the surface parallel to the axis and also at the ends.

2. In a i'otatory or oscillatory mixing .furnace, a furnace body, a furnace lining within the body and a breaking wall extending inward from the general surface of the lining consisting of a. plurality of metallic ribs extending along the wall and exposed to the charge, and refractory material between the ribs.

3. In a rotatory or oscillatory mixing furnace, a furnace body and a refractory lining within the body consisting of a plurality of spiral metallic ribs and refractory material between the ribs, the refractory material between each pair of adjacent ribs extending inward to the longitudinal edges of the ribs near the ribs and, between the ribs, extending inward less than the inward extension of said adjacent ribs, whereby end mixing of the charge will take place when the furnace is in motion.

4. In a rotatory or oscillatory mixing furnace, a furnace body, a furnace lining within the body and a spiral mixing vane in the lining consisting of a plurality of metallic ribs exposed to the charge and extending inward farther than the remaining portion of the lining, and refractory material between v adjoining ribs and extending inward farther a plurality of ribs of greater inward extene sion than those of the lining andrefractory material between the ribs.

6. In a furnace lining, a plurality of metallic ribs generally parallel, other ribs generally transverse with respect to the first and intersecting them, and refractory material between the respective ribs and extending inward substantially the same distance as the ribs.

'7. In a furnace lining, a honeycomb like structure of mutually braced metallic ribs, some generally parallel to and others generally transverse to one another, and refractory material between the ribs. A y

S. In a rotatory or oscillatory puddling furnace, a cylindrical furnace body and a furnace lining within the body having axial undulations, comprising a radially and axially vextending metallic rib following the peak of each undulation, exposed to the charge and spaced more widely fi'oin its neighbor at its outer edge than at its inner edge, and refractory material in the depressions between the peaks and rising to the peaks of the undulations.

9. In a rotatory or oscillatorypuddling furnace, a furnace body and a furnace lining within the body having an undulating inner surface, comprising a metallic rib extending along the peak of each undulation, exposed to the charge, and refractory material in the depressions between the peaks and rising to the peaks of the undulations.

10. In a rotatory or oscillatory puddling furnace, a furnace body and a furnace lining wit-hin the body having an undulating inner surface, comprising a metallic iib extending along the peak of each undulation, exposed to the charge and secured to the furnace body and'refractory material in the depressions between the peaks and rising to the peaks of the undulations.

' CHARLES HART. 

